JP2006317070A - Burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance flame stability by stabilizing auxiliary flames and to attain the use of a lean mixture and reduction of NOx. <P>SOLUTION: A totally aerated burner comprises main flame holes 20 and auxiliary flame holes 21 located outside in the burner width direction of the main flame holes 20. An intermediate part of a mixture passage for supplying a mixture to the auxiliary flame holes 21 is provided with a cross-sectional area enlarged part 27a formed by enlarging the passage cross-sectional area of the mixture passage 27 toward the lower reaches in a mixture flow direction, and capable of forming auxiliary flames. It is preferable to set a passage width (a) to 0.8-1.0 mm, (b) to 1.5-2.0 times as large as the passage width (a), and θ to 20° or less. Thick flame holes can be formed outside the auxiliary flame holes 21 in a thick and thin fuel burner. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a burner that can be applied to a water heater or the like, regarding applicable burners as a low NO _X burner enhanced flame stability of the auxiliary flame is formed on both sides of the main flame.

  The gas combustion burner has a main flame hole and a flame hole forming portion that forms a passage for introducing an air-fuel mixture to the main flame hole, and a vertical plate portion that covers the outside of the flame hole forming portion. It has a burner body provided. The burner main body forms a throat portion into which air and gas are introduced, and a mixing passage portion connected to the throat portion to mix air and gas to form an air-fuel mixture, and the air-fuel mixture from the mixing passage portion to the flame hole forming portion. Is supplied.

As a gas-fired burner, shading burner, but like all the primary burners have been put to practical use conventionally been mainly employed shades burner as low NO _X burner. In this dark and light burner, since the air ratio of the air-fuel mixture supplied to the light flame holes is larger than 1, the light flame alone has poor flame holding properties. Accordingly, the flame holding property is ensured by forming dense flame holes on both sides of the pale flame hole (main flame hole) forming the pale flame and forming the dense flame in the dense flame hole. The rich flame hole is a kind of auxiliary flame, and the rich flame is a kind of auxiliary flame.

However, the dark flame because of the large discharge amount of NO _X, it is difficult to reduce below a certain the NO _X emission gas-fired burner, also forms a light mixture passage and dense mixture path in the burner Therefore, the structure of the burner is complicated and the manufacturing cost is high.
Therefore, recently, it has improved the total primary burners is promoted as a low NO _X burner. A general all-primary burner burns an air-fuel mixture with an air ratio of about 1. Recently, a lean premixed burner that burns a lean air-fuel mixture with an air ratio of about 1.6 has been put into practical use. In all primary burners, auxiliary flame holes are formed on both sides of the main flame hole, and flame holding properties are secured by the auxiliary flames on both sides of the main flame.

  As described above, in both the light and dark burners and in all the primary burners, increasing the stability of the auxiliary flame is very important for ensuring the flame holding performance, but in the conventional gas combustion burner, the stability of the auxiliary flame is stable. There have not been many proposals for effective techniques for enhancing the performance. The air-fuel mixture passage near the lower side (upstream side) of the auxiliary flame hole is formed as a passage having a substantially constant width in the burner width direction, and the auxiliary flame is always formed at the same position with respect to the auxiliary flame hole.

The burner of special structure described in Patent Document 1, in order to reduce the NO _X lowers the flame temperature, is divided by the auxiliary flame holes of the main fire hole of the center of the upper surface of the groove-shaped burner body, that A plurality of main flame holes are formed in the main flame hole portion, a plurality of auxiliary flame holes are formed on the wall surface of the groove-shaped auxiliary flame hole portion, a plurality of auxiliary flame holes are formed on the side surface of the burner body, and A stepped decompression plate is provided with a gap, the passage gap inside the decompression plate is made larger than the passage gap inside the decompression plate, and an auxiliary flame hole is formed in the vertical plate facing the decompression plate. To do.

In the combustion apparatus described in Patent Document 2, as shown in FIG. 20, a flare hole (main flame hole) is formed by a flame hole member, and a rich flame hole is formed at the upper end of the concentrated mixed gas passage part. An intermediate flame hole is formed between the flame hole and the pale flame hole to form an intermediate flame with a mixed gas having an intermediate concentration.
Japanese Patent No. 2844898 Japanese Patent No. 2682446

  In general, in the flame hole portion (main flame hole, auxiliary flame hole) of the burner, a flame is formed at a position where the flow velocity of the air-fuel mixture flowing upward and the flame propagation velocity propagating downward are balanced. In the concentration burner, the rich flame formed in the rich flame hole with a rich mixture (air ratio of about 0.6) becomes lifted when the air amount in the mixture is insufficient, so the light flame formed in the main flame hole The flame tends to become an unstable flame with vertical vibration.

In a lean premixed burner or the like of recent all primary burners, an air-fuel mixture with an air ratio increased to about 1.6 is often adopted in order to reduce NO _{x in} the exhaust gas. In such a lean air-fuel mixture, the flow rate of the air-fuel mixture increases compared to a normal air-fuel mixture with an air ratio of about 1.0, so the air-flow rate of the air-fuel mixture in the auxiliary flame hole increases and the auxiliary flame lift becomes significant. As a result, the auxiliary flame becomes unstable and it is difficult to ensure flame holding properties.

  As a countermeasure, it is possible to increase the flame width in the burner width direction of the auxiliary flame hole and increase the cross-sectional area of the passage near the lower side of the auxiliary flame hole to reduce the flow rate of the air-fuel mixture. When the burner is operated in a low load state, the air-fuel mixture flow rate is remarkably lowered and it becomes easy to backfire. In particular, in the conventional gas combustion burner, the position of the auxiliary flame with respect to the auxiliary flame hole is constant, and the mixture flow velocity of the auxiliary flame hole increases in proportion to the increase in the flow rate of the air-fuel mixture. Thus, it was difficult to ensure stable flame holding property, and TDR (Turn Down Ratio) could not be expanded.

An object of the present invention, the auxiliary flame to stabilize enhance flame stability, enabling adoption and low NO _X reduction of lean, and the like to allow a larger TDR.

  The burner according to claim 1 is a burner provided with a main flame hole and an auxiliary flame hole located on the outer side in the burner width direction of the main flame hole. A cross-sectional area enlarging part in which the cross-sectional area of the air-fuel mixture path is enlarged toward the downstream side in the air-fuel mixture flow direction, and a cross-sectional area enlarging part capable of forming an auxiliary flame is provided. This burner can be applied to a light and dark burner, and can also be applied to all primary burners.

  Regarding the flow of the air-fuel mixture in the air-fuel mixture passage for supplying the air-fuel mixture to the auxiliary flame hole, the flow velocity upstream of the cross-sectional area enlarged portion is higher than the flow velocity downstream of the cross-sectional area enlarged portion. Therefore, in the normal operation state in which the air-fuel mixture flow rate is not so small, the upstream flow velocity becomes very large. Therefore, the auxiliary flame hole at the upper end of the air-fuel mixture passage (the auxiliary flame hole outside the main flame hole) ) To form an auxiliary flame. On the other hand, in the low load operation state, the flow velocity on the downstream side becomes very small, so that the auxiliary flame moves to the back in the mixture passage, and the auxiliary flame is formed in the cross-sectional area enlarged portion. .

  The burner according to claim 2 is the invention according to claim 1, wherein the mixture passage on the upstream side in the mixture flow direction with respect to the cross-sectional area enlarged portion has a plurality of mixture passage portions having different passage widths in the burner width direction. It is characterized by.

  According to a third aspect of the present invention, in the invention of the first aspect, the cross-sectional area enlarged portion is formed in at least a part of the auxiliary flame hole in the burner length direction. This burner can be applied to a light and dark burner, and can also be applied to all primary burners.

  The auxiliary flame hole portion and the cross-sectional area enlarged portion formed in a part of the auxiliary flame hole operate in the same manner as in the first aspect. That is, in the low-load operation state, the auxiliary flame moves to the back of the auxiliary flame hole to form an auxiliary flame in the cross-sectional area enlarged portion, and in the medium-load operation state, the auxiliary flame is located above the cross-sectional area enlarged portion. The auxiliary flame is formed in the other part of the auxiliary flame hole, and the auxiliary flame is formed at least in the part of the auxiliary flame hole in the high load operation state. Thus, at least three types of auxiliary flames can be switched according to the operating state of the burner.

  According to a fourth aspect of the present invention, in the burner according to any one of the first to third aspects, the first communication hole that supplies the air-fuel mixture to the air-fuel mixture passage portion that communicates with a part of the auxiliary flame hole, It is characterized in that the hole area is larger than that of the second communication hole for supplying the air-fuel mixture to the air-fuel mixture passage portion communicating with the other part.

  The burner according to claim 5 is a light flame hole in which the main flame hole makes a light flame with a light mixture, and the mixed flame is concentrated on the outer side of the auxiliary flame hole in the burner width direction. It is characterized by the formation of a deep flame hole that creates a deep flame with the air.

The burner according to claim 6 is the invention according to any one of claims 1 to 5, wherein when the burner is in a low-load operation state, an auxiliary flame is formed in the cross-sectional area enlarged portion, and when the burner is in a high-load operation state, An auxiliary flame is formed in the auxiliary flame hole.
According to a seventh aspect of the present invention, in the burner according to any one of the first to sixth aspects, the main flame hole is formed of a plurality of longitudinally oriented intermediate plates, and the auxiliary flame hole is the vertical of the outermost intermediate plate and the burner body. It is formed by a board part.

  According to the first aspect of the present invention, in the middle portion of the air-fuel mixture passage that supplies the air-fuel mixture to the auxiliary flame hole, the cross-sectional area of the passage is enlarged toward the downstream side in the air-fuel mixture flow direction, and the auxiliary flame can be formed. Due to the increased area, an auxiliary flame is formed in the auxiliary flame hole outside the main flame hole (the auxiliary flame hole at the upper end of the air-fuel mixture passage) during normal and high-load operation, and in low-load operation Can form an auxiliary flame in the cross-sectional area enlarged portion.

Therefore, the flame holding property of the auxiliary flame during the low load operation state can be enhanced, and the auxiliary flame hole in the burner width direction is expanded to enhance the flame holding property of the auxiliary flame during the high load operation state. It becomes possible. Therefore, it is possible to burn the lean mixture with enhanced air ratio stably enables low NO _X of the exhaust, also can expand the width of the maximum air-fuel mixture flow rate to the minimum air-fuel mixture flow rate Therefore, the TDR can be expanded.

According to the invention of claim 2, the mixture passage on the upstream side in the mixture flow direction with respect to the cross-sectional area enlarged portion of claim 1 has a plurality of mixture passage portions having different passage widths in the burner width direction. A plurality of auxiliary flames can be formed in the cross-sectional area enlarged portion. That is, a low load the load in the ascending order in the operating state Q _1, Q ₂ · ·, When W _1, W ₂ · · in ascending order of the above passage width, respectively passage when the load Q _1, Q ₂ · · Auxiliary flames are formed at the site of the enlarged cross-sectional area corresponding to the widths W ₁ , W ₂ . Thus, the effect of claim 1 can be further enhanced.

  According to invention of Claim 3, since the said cross-sectional area enlarged part is formed in at least one part of the burner length direction among the said auxiliary flame holes, about the said cross-sectional area enlarged part, the effect similar to Claim 1 is provided. The auxiliary flame formation position can be switched in plural ways according to the air-fuel mixture flow rate.

  According to the burner according to claim 4, in the burner according to any one of claims 1 to 3, the first communication hole for supplying the air-fuel mixture to the air-fuel mixture passage portion communicating with a part of the auxiliary flame hole is provided with the auxiliary flame hole. Since it was configured to have a larger hole area than the second communication hole for supplying the air-fuel mixture to the air-fuel mixture passage portion communicated with the other part, the air-fuel mixture flow rate to be supplied to a part of the auxiliary flame hole, The air-fuel mixture flow rate supplied to the other part of the auxiliary flame hole can be set appropriately to ensure the effect of improving the flame holding property.

  According to the burner of claim 5, the main flame hole is a pale flame hole that creates a pale flame with a pale mixture, and a rich flame hole that creates a dense flame with a dense mixture on the outer side in the burner width direction of the auxiliary flame hole. Since it formed, the auxiliary flame and the rich flame are formed outside the pale flame, and the flame holding property in the dark and light burner can be secured.

  According to the burner of claim 6, when the burner is in a low load operation state, an auxiliary flame is formed in the cross-sectional area enlarged portion, and when the burner is in a high load operation state, an auxiliary flame is formed in the auxiliary flame hole. Therefore, as described in claims 1 and 3, a stable auxiliary flame can be formed regardless of the load of the burner.

  According to the burner of claim 7, the main flame hole is formed by a plurality of vertically oriented intermediate plates, and the auxiliary flame hole is formed by the outermost intermediate plate and the vertical plate portion of the burner body. The present invention can be applied to all primary burners having a typical structure.

  The burner according to the present invention is a burner having a main flame hole and an auxiliary flame hole located on the outer side in the burner width direction of the main flame hole, in the middle part of the gas mixture passage for supplying the air-fuel mixture to the auxiliary flame hole, A cross-sectional area enlarging part in which the cross-sectional area of the air-fuel mixture path is enlarged toward the downstream side in the air-fuel mixture flow direction, and a cross-sectional area enlarging part capable of forming an auxiliary flame is provided.

Embodiments of the present invention will be described below with reference to the drawings.
In this embodiment, the present invention is applied to a gas combustion burner of a gas combustion apparatus of a gas hot water supply apparatus. As shown in FIGS. 1 to 3, the gas hot water supply device 1 includes a gas combustion device 2 and a heat exchanger 3 connected to the upper end of the gas combustion device 2. The gas combustion device 2 includes a blower unit 4 and a combustion unit 5, and the blower unit 4 includes a fan case 6, a fan 7, a fan motor 8, and the like, and combustion air from the blower unit 4 to the combustion unit 5. Is blown.

  As shown in FIGS. 1 to 3, the combustion unit 5 supplies a burner case 9, a plurality of gas combustion burners 10 accommodated in the burner case 9, and fuel gas to the plurality of gas combustion burners 10. Cooling that flows along a plurality of gas nozzles 11, an air flow passage 13 that guides air supplied from the blower unit 4 to the air inlets 12 of the plurality of gas combustion burners 10, and four front and rear wall surfaces of the burner case 9. It has four partition plates 14 forming an air passage. A flat secondary air passage is formed between the gas combustion burner 10 and the gas combustion burner 10, and secondary air introduced from the air flow passage 13 is supplied to the secondary air passage.

  As shown in FIGS. 4 to 6, the gas combustion burner 10 of the present embodiment is an all-primary burner. The gas combustion burner 10 includes a burner body 15 and a plurality of (for example, six) burners inside the burner body 15. Middle plate 16. The burner body 15 is formed by press-molding a thin stainless plate (for example, a plate thickness of 0.3 mm), and the intermediate plate 16 is configured by press-molding a thin stainless plate (for example, a plate thickness of 0.3 mm). The throat portion 17 into which the gas and the combustion air flow, the mixing passage portion 18 for mixing the gas and the combustion air flowing in from the throat portion 17, and the flame hole formation that forms the main flame hole 20 and the auxiliary flame hole 21. Part 22.

  The flame hole forming part 22 has, for example, a main flame hole forming part 23 that forms the main flame hole 20 with the six intermediate plates 16, and the burner body 15 has an outer side in the burner width direction of the main flame hole 20. A side plate 24 constituting a part is disposed, and an auxiliary flame hole 21 is formed at an upper end portion between the side plate 24 and the inner middle plate 16. The six intermediate plates 16 are welded to the side plates 24 at a plurality of press-formed joints, and a plurality of (for example, 14) main flame holes 20 are formed in the main flame hole forming portion 23 as shown in FIG. The auxiliary flame holes 21 are formed of the side plates 24 and the intermediate plate 16 on the outer sides of both sides of the main flame holes 20 in the burner width direction.

Next, each main flame hole 20 and its peripheral structure in the flame hole forming part 22 will be described.
As shown in FIG. 7 to FIG. 9, a main flame passage 25 for supplying an air-fuel mixture to the main flame hole 20 is formed by six middle plates 16, and the outermost middle plate 16 and the outer side plate 24 An auxiliary flame passage 27 for supplying air-fuel mixture to the auxiliary flame hole 21 is formed. In the middle part (middle stage) of the auxiliary flame passage 27, the cross-sectional area enlargement portion 27a in which the passage cross-sectional area is suddenly enlarged toward the downstream side in the air-fuel mixture flow direction and the auxiliary flame 21a can be formed is enlarged. A portion 27a is formed.

  The auxiliary flame passage 27 is vertical along the intermediate plate 16, and the passage width of the auxiliary flame passage 27 abruptly expands toward the side plate 24 at the cross-sectional area enlarged portion 27a, thereby improving the stability of the auxiliary flame 21a. In order to raise, the upper end part of the side plate 24 protrudes above the upper end of the intermediate plate 16 by a predetermined length.

  The relationship between the passage width a of the lower passage 28 below (upstream) the cross-sectional area enlarged portion 27a and the passage width (a + b) of the upper passage 29 above (downstream) above the cross-sectional area enlarged portion 27a is, for example, a: b = 1: (1.5 to 2.0), the passage width a is set to 1.0 mm or less to prevent backfire, and the inclination angle θ of the side plate 24 at the cross-sectional area enlarged portion 27a. Is set to 20 degrees or less. Specifically, it is desirable to set a = 0.8 to 1.0 mm and b = 1.5 mm. The passage width (a + b) of the upper passage 29, that is, the passage width of the auxiliary flame hole 21 is larger than the passage width of the auxiliary flame hole of a normal all-primary burner.

  In the portion corresponding to the lower portion of the lower passage 28, the outermost intermediate plate 16 is formed with a plurality of (for example, two to three) communication holes 26 for leading the air-fuel mixture to the auxiliary flame passage 27. Yes. For example, a lean gas / air mixture having an air ratio of 1.6 is supplied to the main flame hole 20 from the main flame passage 25 to form a main flame 20a in the main flame hole 20, and the auxiliary flame passage 27 has a main flame 20a. An air-fuel mixture similar to that described above is led out from the flame passage 25 through the communication hole 26, and an auxiliary flame 21 a is formed in the auxiliary flame hole 21.

Next, the operation and effect of the burner 10 will be described.
Regarding the flow of the air-fuel mixture in the auxiliary flame passage 27, the flow velocity in the lower passage 28 upstream from the cross-sectional area enlarged portion 27a is higher than the flow velocity in the upper passage 29 downstream from the cross-sectional area enlarged portion 27a. . Therefore, in the normal medium and high load operation state where the air-fuel mixture flow rate is not small, the upstream flow velocity becomes very large. Therefore, as shown in FIG. 10-2, the auxiliary flame hole at the upper end of the auxiliary flame passage 27 An auxiliary flame 21 a is formed at 21. On the other hand, in the low-load operation state, the downstream flow velocity is very small. Therefore, as shown in FIG. 10A, the auxiliary flame 21a is located in the back of the upper passage 29 (on the lower side in FIG. 10A). ), The auxiliary flame 21a is formed in the cross-sectional area enlarged portion 27a. At this time, the auxiliary flame 21a is pressed toward the intermediate plate 16 by the vortex generated by the step of the cross-sectional area enlarged portion 27a and is formed along the intermediate plate 16, so that a stable auxiliary flame 21a is formed. Further, since the heat from the auxiliary flame 21a is effectively propagated to the intermediate plate 16, the flame holding property of the main flame 20a can be enhanced.

Accordingly, the flame holding ability of the main flame 20a and the auxiliary flame 21a in the low load operation state can be enhanced, and the passage width (a + b) of the auxiliary flame hole 21 is also enlarged as compared with the auxiliary flame hole of a normal burner. Therefore, the flame holding property of the auxiliary flame 21a during the high load operation state can be enhanced. Therefore, it becomes possible to stably burn the lean mixture enables low NO _X of the exhaust, also it is possible to expand the TDR for possible expansion of the width of the maximum combustion amount to a minimum combustion amount it can.

An example in which the auxiliary flame hole 21 and its peripheral structure of the first embodiment are partially changed will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIGS. 11 to 13, in this burner 10 </ b> A, the lower passage 28 on the upstream side in the mixed gas flow direction with respect to the cross-sectional area enlarged portion 27 a has two lower passage portions having different passage widths in the burner width direction. 28a and 28b. The lower passage portions 28a and 28b communicate with each other.

  The relationship between the passage width a of the lower passage portion 28a and the passage width c of the lower passage portion 28b is c <a, and the lower passage portion 28a is located on one side of the main flame hole 20 as shown in FIG. The lower passage 28 is formed in the left half, and the lower passage 28 b is formed in the right half of the lower passage 28. On the other side of the main flame hole 20, the lower passage portion 28 a is formed in the right half portion of the lower passage 28, and the lower passage portion 28 b is formed in the left half portion of the lower passage 28. The passage width a is, for example, 0.8 to 1.0 mm, the passage width c is, for example, 0.5 mm, and b in the passage width (a + b) of the upper passage 29 is, for example, 1.5 to 2.0 mm.

  As shown in FIG. 13, on each side of the main flame hole 20, communication holes 26 a and 26 b communicating with the lower passage portions 28 a and 28 b are formed in the outermost intermediate plate 16. The flow rate of the air-fuel mixture in the lower passage portions 28a and 28b is v1 and v2, and the flow velocity of the air-fuel mixture in the auxiliary flame holes 21c and 21d above the lower passage portions 28a and 28b is v3 and v4. Since the holes 26a and 26b have the same size, a relationship such as v4 = v3 <v1 <v2 is substantially established.

The operation and effect of this burner 10A will be described.
The burner 10A basically has the same operations and effects as the burner 10 of the first embodiment. During the middle and high load operation state, the auxiliary flame 21 a is formed in the auxiliary flame holes 21 on both sides of the main flame hole 20. During the low load operation state, the auxiliary flame 21a moves to the back (lower side in FIG. 11), and the auxiliary flame 21a is formed at the site of the cross-sectional area enlarged portion 27a. At this time, a stable auxiliary flame 21a is formed at least in the portion of the cross-sectional area enlarged portion 27a corresponding to the lower passage portion 28a of the passage width a. By the auxiliary flame 21a, the auxiliary flame 21a is also maintained in the portion of the cross-sectional area enlarged portion 27a corresponding to the lower passage portion 28b of the passage width c.

  When the load is further lowered, a stable auxiliary flame 21a is formed at least in the cross-sectional area enlarged portion 27a corresponding to the lower passage portion 28b of the passage width c. By the auxiliary flame 21a, the auxiliary flame 21a is also maintained in the portion of the cross-sectional area enlarged portion 27a corresponding to the lower passage portion 28a of the passage width a. Thus, by having two kinds of passage widths a and c suitable for the combustion amount (mixture flow rate) in the low load operation state of the burner 10A, three types of stable auxiliary flames are provided according to the load state of the burner 10A. 21a can be formed, and the flame holding ability of the auxiliary flame 21a and the flame holding ability of the main flame 20a can be significantly improved. In addition, there are substantially the same operations and effects as the burner 10 of the first embodiment.

  As a modification of the burner 10A, the communication holes 26a and 26b in FIG. 13 have a communication hole 26a corresponding to the lower passage portion 28a larger in diameter than the communication hole 26b corresponding to the lower passage portion 28b. It may be configured so that the relationship of v4 <v3 <v1 <v2 is established with respect to the flow rate of the air-fuel mixture. In this case, the auxiliary flame 21a formed in the auxiliary flame hole portion 21d is stable during the high load operation state, and the auxiliary flame 21a formed in the auxiliary flame hole portion 21c is stable during the medium and high load operation state. In the low load operation state, it is almost the same as described above. In this way, four stable auxiliary flames 21a can be formed according to the load state of the burner 10A.

An example in which the auxiliary flame hole 21 and its peripheral structure of the second embodiment are partially changed will be described. However, the same components as those in the first and second embodiments are denoted by the same reference numerals and the description thereof is omitted.
As shown in FIG. 14, in the burner 10B, the lower passage 28 on the upstream side in the air-fuel mixture flow direction from the cross-sectional area enlarged portion 27a includes two lower passage portions 28a having the same passage width a, One lower passage portion 28c formed between the passage portions 28a and having a passage width c (where c <a) is smaller than the passage width a of the lower passage portion 28a. The three lower passage portions 28a, 28c, and 28a communicate with each other, and the widths a, b, and c are the same as those in the second embodiment.

  As shown in FIG. 15, the outermost middle plate 16 corresponding to the lower passage 28 has communication holes 26a and 26a for leading the air-fuel mixture to the two lower passage portions 28a and 28a, and one lower passage. A communication hole 26c for leading the air-fuel mixture is formed in the portion 28c, and the communication hole 26a is formed with a larger diameter than the communication hole 26c. The diameter of the communication hole 26a is, for example, 1.5 to 2.0 mm, and the diameter of the communication hole 26c is, for example, 1.0 mm.

  As shown in FIG. 15, instead of changing the diameters of the communication holes 26a, 26c, the number of communication holes is changed as shown in FIG. 16, and the same as the communication hole 26c instead of the larger communication hole 26a. Two communication holes 26d having a diameter may be formed. Here, regarding the flow rate of the air-fuel mixture, if the flow rates in the auxiliary flame holes above the lower passage portions 28a and 28c are v5 and v6, and the flow rates v7 and v8 in the lower passage portions 28a and 28c are v6 <v5 <v7. It is desirable to configure so that <v8.

  This burner 10B basically has the same operations and effects as the burner of the second embodiment, but has an appropriate amount of air-fuel mixture (low load operation) according to the passage widths a and c of the lower passage portions 28a and 28c. In some cases, four types of auxiliary flames 21a are formed by supplying the lower passage portions 28a and 28c with an appropriate amount of air-fuel mixture for forming the auxiliary flames at the cross-sectional area enlarged portion 27a. And the stability of the auxiliary flame 21a can be further enhanced.

An example in which the auxiliary flame hole 21 and its peripheral structure of the third embodiment are partially changed will be described. However, the same code | symbol is attached | subjected to the thing similar to the said Examples 1-3, and description is abbreviate | omitted.
As shown in FIG. 17, in this burner 10 </ b> C, a part of the auxiliary flame hole 21 in the burner length direction has a larger flame hole width than the burner width direction flame hole width of the other part of the auxiliary flame hole 21. The lower passage 28 is formed in the two auxiliary flame holes 21 </ b> A and supplies the air-fuel mixture to the two auxiliary flame holes 21 </ b> A out of the auxiliary flame passages 27 that supply the air-fuel mixture to the auxiliary flame holes 21. The cross-sectional area enlargement part 27a, which is a cross-sectional area enlargement part 27a in which the passage cross-sectional area of the lower side passage 28 is suddenly enlarged toward the downstream side in the air-fuel mixture flow direction and can form the auxiliary flame 21a, is provided respectively. ing.

An auxiliary flame hole 21A is formed at a predetermined length portion on both ends of the auxiliary flame hole 21, and an auxiliary flame hole 21B whose width is not enlarged is formed between these auxiliary flame holes 21A. The passage widths a and c of the lower passage portion 28 and the passage width of the auxiliary flame hole portion 21A are the same as those in the first embodiment, and the passage width of the auxiliary flame hole portion 21B is the passage width of the auxiliary flame hole portion 21A. It is formed smaller than. The communication holes formed in the outermost intermediate plate 16 are the same as those in the second and third embodiments. This burner 10C has substantially the same operations and effects as the burner 10B of the third embodiment.
In FIG. 17, the auxiliary flame hole 21 </ b> A may be formed on the right (or left) half and the auxiliary flame hole 21 </ b> B may be formed on the left (or right) half in FIG. 17.

An example in which the auxiliary flame hole 21 and its peripheral structure of the first embodiment are partially changed will be described. However, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIGS. 18 and 19, the burner 10 </ b> D includes a main flame hole 20 as a pale flame hole, an auxiliary flame hole 21 outside the burner width direction, and a concentrated flame hole 21 </ b> D outside the auxiliary flame hole 21. A light and dark burner having The rich flame hole 21D is a kind of auxiliary flame hole.

  Examples of the flame hole forming portion 22, the main flame hole forming portion 23, the main flame hole 20, the auxiliary flame hole 21, the main flame passage 25, the auxiliary flame passage 27, the cross-sectional area enlarged portion 27a, and the like 1, for example, a light mixture having an air ratio of 1.6 is supplied to the main flame passage 25 and the auxiliary flame passage 27. The auxiliary flame hole 21 is formed by a side plate 24 which is a part of the burner body, and a cross-sectional area enlarged portion 27a having a rapidly enlarged passage width is formed in the middle portion of the auxiliary flame passage 27, and the upper end of the side plate 24 is It is at the same height as the upper end of the middle plate 16.

  An outer plate 30 is disposed outside the side plate 24 and joined thereto, and a rich mixture passage 31 is formed between the side plate 24 and the outer plate 30, and a rich flame hole is formed at the upper end of the rich mixture passage 31. 21D is formed, and the rich mixture passage 31 is supplied with a rich mixture having an air ratio of 0.6, for example. In order to stabilize the rich flame 21e, the upper end portion of the outer plate 30 is extended above the upper end of the side plate 24 by a predetermined length. The light / dark burner 10D has the same effects and effects as the first embodiment for the main flame 20a and the auxiliary flame 21a, and also forms the dark flame 21e by forming the dark flame hole 21D. Furthermore, the flame holding property of the main flame 20a can be secured by the rich flame 21e. Furthermore, the flame holding property of the auxiliary flame 21a can be enhanced by the rich flame 21e.

Next, an example in which the structure of the light / dark burner 10D is partially changed will be described.
1] As shown in FIG. 20, the upper end of the side plate 24 extends a predetermined length above the upper end of the intermediate plate 16, and the upper end of the outer plate 30 extends a predetermined length above the upper end of the side plate 24. It is being done. Therefore, the stability of the auxiliary flame 21a and the stability of the rich flame 21e are increased.

  2] As shown in FIG. 21, the portion of the side plate 24 that forms the auxiliary flame passage 27 is formed in a vertical plate shape, and the outermost intermediate plate 16 near the lower side of the auxiliary flame hole 21 assists outward. A bulging portion 32 bulging in a trapezoidal shape into the flame passage 27 is formed so as to extend in the horizontal direction, and a cross-sectional area enlarged portion 27 a in which the passage area rapidly expands is formed at the upper end of the bulging portion 32. . The passage width at the bulging portion 32 is set to 1.0 mm or less.

The upper end of the side plate 24 is at the same height as the upper end of the middle plate 16, and the upper end portion of the outer plate 30 protrudes a predetermined length above the upper end of the side plate 24. The auxiliary flame 21a is formed in the cross-sectional area enlarged portion 27a during the low load operation state, and the auxiliary flame 21a is formed in the auxiliary flame hole 21 during the normal load operation state. In this concentration burner, when the amount of air in the mixture decreases, the rich flame 21e becomes lifted, but the auxiliary flame 21a is located below the rich flame 21e, so the auxiliary flame 21a is the rich flame 21e. The stable state is maintained without being affected by. Therefore, the stability of the auxiliary flame 21a can be improved and the flame holding property of the main flame 20a can be improved.

3] As shown in FIG. 22, in the burner of FIG. 21, the upper end portion of the side plate 24 is a portion of a predetermined length on the upper end side of the side plate 24 in view of being heated by the auxiliary flame 21a and the rich flame 21e. The thickness from the upper end to the portion facing the bulging portion 32 is increased by about twice the thickness (for example, 0.5 to 0.6 mm) of the thickness of the other portion (for example, 0.3 mm). It is formed in the part 24a. The plate thickness increasing portion 24a is formed by welding and joining plate members having a large plate thickness. As shown in FIG. 23, the plate thickness increasing portion 24a is configured by a hemming portion 33 which is folded back and adhered. May be.
4] The burner fuel of the above embodiment may be a gasified liquid fuel such as kerosene as well as city gas.

It is a front view of the gas hot-water supply apparatus of Example 1 of this invention. It is a top view of the gas combustion apparatus of the said gas hot-water supply apparatus. It is a side view of the said gas combustion apparatus. It is a top view of a gas combustion burner. It is a side view of a gas combustion burner. It is a front view of a gas combustion burner. It is a principal part expansion longitudinal cross-sectional view of a gas combustion burner. It is a principal part longitudinal cross-sectional view of a gas combustion burner. It is a principal plane part of a gas combustion burner. It is explanatory drawing of the main flame and auxiliary flame at the time of the low load driving | running state of a gas combustion burner. It is explanatory drawing of the main flame and auxiliary flame at the time of a medium and high load operation state of a burner. It is a principal part longitudinal cross-sectional view of the gas combustion burner of Example 2. FIG. It is a principal part top view of the said burner. It is a figure which shows the intermediate plate and communicating hole of the said burner. 6 is a plan view of a main part of a gas combustion burner according to Embodiment 3. FIG. It is a figure which shows the intermediate plate and communicating hole of the said burner. It is a figure which shows the intermediate plate and communicating hole of the said burner. 6 is a plan view of a main part of a gas combustion burner according to Embodiment 4. FIG. It is principal part sectional drawing of the gas combustion burner of Example 5. FIG. It is a principal part expanded sectional view of the said burner. It is principal part sectional drawing of the modification which deform | transformed a part of burner of FIG. It is principal part sectional drawing of another modification which deform | transformed a part of burner of FIG. It is principal part sectional drawing of the modification which deform | transformed a part of burner of FIG. It is sectional drawing of the modification of the board thickness increase part of the burner of FIG.

Explanation of symbols

10, 10A, 10B, 10C, 10D Gas combustion burner 16 Middle plate 20 Main flame hole 21 Auxiliary flame hole 21A Auxiliary flame hole portion 21e Rich flame 21D Rich flame holes 26, 26a to 26d Communication hole 27 Auxiliary flame passage 27a Cross-sectional area Enlarged portion 28 Lower passage 28a, 28b Lower passage portion 29 Upper passage

Claims (7)

In a burner having a main flame hole and an auxiliary flame hole located outside the burner width direction of the main flame hole,
An auxiliary flame is formed in the middle part of the air-fuel mixture passage for supplying the air-fuel mixture to the auxiliary flame hole, which is a cross-sectional area enlarged portion in which the cross-sectional area of the air-fuel mixture passage is enlarged toward the downstream side in the air-fuel mixture flow direction. A burner characterized by providing a possible cross-sectional area enlargement part.   2. The burner according to claim 1, wherein the mixture passage on the upstream side in the mixture flow direction with respect to the cross-sectional area enlarged portion has a plurality of mixture passage portions having different passage widths in the burner width direction.   The burner according to claim 1, wherein the cross-sectional area enlarged portion is formed in at least a part of the auxiliary flame hole in the burner length direction.   A first communication hole that supplies an air-fuel mixture to a mixture passage portion that communicates with a part of the auxiliary flame hole, and a second communication that supplies an air-fuel mixture to a mixture passage portion that communicates with the other part of the auxiliary flame hole The burner according to any one of claims 1 to 3, wherein the burner is configured to have a larger hole area than the hole.   The main flame hole is a pale flame hole that creates a pale flame with a pale mixture, and a dense flame hole that creates a dense flame with a dense mixture is formed outside the auxiliary flame hole in the burner width direction. The burner in any one of 1-4.   The auxiliary flame is formed in the cross-sectional area enlarged portion when the burner is in a low load operation state, and the auxiliary flame is formed in the auxiliary flame hole when the burner is in a high load operation state. The burner according to any one of 5. The main flame hole is formed by a plurality of vertically oriented intermediate plates, and the auxiliary flame hole is formed by an outermost intermediate plate and a vertical plate portion of a burner body. Burner according to crab.

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