Gas burners and boilers

Abstract

The gas burner (1) according to one aspect of the present invention comprises: a fuel supply pipe (10) that extends in a predetermined combustion air-jetting direction and is supplied with fuel gas; an air jet opening (40) that opens in an annular region concentric with the fuel supply pipe (10) as viewed in the combustion air-jetting direction, and through which combustion air is blown along the fuel supply pipe (10) in the combustion air-jetting direction; a separation structure (70) that at least partially separates the flow of the combustion air from the fuel supply pipe (10); and an outflow structure having a fuel outlet (81) that allows the fuel gas to flow out of the fuel supply pipe (10) in a low pressure area that is formed by the separation structure (70) separating the flow of the combustion air.

Description

[Technical field]

[0001] The present invention relates to a gas burner and a boiler. This application claims priority based on Japanese Patent Application No. 2021-56809, filed in Japan on March 30, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] For example, in a gas-fired boiler or the like, a technology is known for providing a premixed burner that reliably supplies a required amount of gas to the burner even when the gas supply pressure is relatively low (for example, Patent Document 1). Patent Document 1 discloses a boiler that includes a blower that supplies combustion air to the burner, and a gas suction mechanism that is provided at the suction port of the blower. The gas suction mechanism is configured with a Venturi tube, and as air is sucked into the suction port of the blower, it sucks in gas from the gas supply path and sends it to the suction port together with the air. Since the gas suction mechanism uses the suction of air into the blower to suck in gas, a desired amount of gas can be supplied to the burner even when the gas supply pressure is relatively low.

[0003] It is also known to use low-pressure by-product gases (such as hydrogen gas) generated in the product manufacturing process in by-product facilities such as plant facilities as fuel gas (for example, Patent Document 2). In the by-product gas utilization system of Patent Document 2, hydrogen gas supplied from the by-product facility is boosted by a booster and supplied to a hydrogen gas tank, and the number of boilers is controlled based on the pressure value in the hydrogen gas tank, thereby consuming the by-product gas, the amount of which fluctuates greatly, without waste, and enabling it to be efficiently utilized as energy. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-190646 A [Patent Document 2] JP 2020-20543 A Summary of the Invention [Problem to be solved by the invention]

[0005] When using gases such as hydrogen that have low ignition energy and a high combustion rate, or biogas that contains impurities such as sulfur, as the fuel gas, the configuration of sucking the fuel gas with a blower as in Patent Document 1 is not preferable from a safety standpoint. In addition, when using by-product hydrogen with a low supply pressure as the fuel gas, boosting the fuel gas with a booster not only requires initial costs for the equipment and construction, but also running costs such as the power consumption of the booster. For this reason, there has been a demand for technology that does not require boosting the fuel gas pressure, or technology that can suppress the amount of boost.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a gas burner capable of using a fuel gas with a low supply pressure. [Means for solving the problem]

[0007] A gas burner according to one embodiment of the present invention comprises a fuel supply pipe extending in a predetermined combustion air ejection direction and through which fuel gas is supplied, an air ejection port opening into an annular region concentric with the fuel supply pipe when viewed in the combustion air ejection direction and ejecting combustion air along the fuel supply pipe in the combustion air ejection direction, a separation structure which at least partially separates the combustion air flow from the fuel supply pipe, and an outlet structure having a fuel outlet which causes the fuel gas to flow out from the fuel supply pipe into a low-pressure region formed by the separation structure separating the combustion air flow.

[0008] In the above-described gas burner, the peeling structure may include a peeling member protruding from a peripheral surface of the fuel supply pipe.

[0009] In the above-mentioned gas burner, the peeling structure may be a reduced diameter portion formed in the middle or at the terminal end of the fuel supply pipe.

[0010] In the above-mentioned gas burner, the fuel outlet may be an opening formed in the fuel supply pipe.

[0011] In the above-mentioned gas burner, the outflow structure may have an outflow nozzle extending from the fuel supply pipe and having the fuel outflow outlet formed so as to open toward the downstream side in the combustion air ejection direction rather than toward the radial direction of the fuel supply pipe.

[0012] A boiler according to one embodiment of the present invention comprises the above-mentioned gas burner, and a boiler body arranged to surround the gas burner, having a plurality of water tubes extending in the direction of the combustion air ejection, and defining a flow path for flowing the combustion exhaust gas from the gas burner in the axial direction of the plurality of water tubes. Effect of the Invention

[0013] According to the present invention, it is possible to provide a gas burner and a boiler that can use a fuel gas with a low supply pressure. [Brief description of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a boiler according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the configuration of a gas burner of the boiler of FIG. [Diagram 3] 3 is a view of the gas burner in FIG. 2 as viewed from the downstream side in the direction of combustion air ejection. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of a gas burner according to a second embodiment of the present invention. [Diagram 5] FIG. 4 is a cross-sectional view showing the configuration of a gas burner according to a third embodiment of the present invention. [Figure 6] FIG. 11 is a cross-sectional view showing the configuration of a gas burner according to a fourth embodiment of the present invention. [Figure 7] FIG. 11 is a cross-sectional view showing the configuration of a gas burner according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing the configuration of a boiler 100 equipped with a gas burner 1 according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view showing the configuration of the gas burner 1. Fig. 3 is a view of the gas burner 1 as viewed from the downstream side in the combustion air ejection direction.

[0016] The boiler 100 includes a gas burner 1 that forms a flame extending in a predetermined combustion air ejection direction (vertical direction in this embodiment), and a boiler body 110 that is heated by the combustion exhaust gas of the gas burner 1. The boiler 100 itself is one embodiment of the boiler according to the present invention.

[0017] The can body 110 is disposed so as to surround the gas burner 1, and has a plurality of water tubes 111 extending in the combustion air ejection direction (vertical direction), a lower header 112 connecting the lower ends of the plurality of water tubes 111, and an upper header 113 connecting the upper ends of the plurality of water tubes 111. The can body 110 defines a flow path through which the combustion exhaust gas from the gas burner 1 flows in the axial direction of the plurality of water tubes 111.

[0018] In the can body 110, the multiple water tubes 111 are arranged in a double ring shape when viewed from the injection direction of the gas burner 1. Except for the end of the inner water tube 111 opposite the gas burner 1, the water tubes 111 adjacent in the circumferential direction are connected to each other directly or by a band-shaped member and are arranged so that the combustion exhaust gas cannot pass through. As a result, the combustion exhaust gas from the gas burner 1 passes through the space inside the inner water tube 111, passes through the gaps between the water tubes 111 at the end opposite the gas burner 1, and passes through the space between the inner water tube 111 and the outer water tube 111 in the reverse direction before being discharged to the outside.

[0019] The gas burner 1 comprises a fuel supply pipe 10 extending in the direction of combustion air ejection, a wind box 20 arranged to surround the upstream portion of the fuel supply pipe 10, an air supply pipe 30 extending from the wind box 20 so as to be positioned outside the fuel supply pipe 10, a plurality of air ejection ports 40 provided at the tip of the air supply pipe 30 so as to be positioned around the fuel supply pipe 10, an inner wall pipe 50 arranged inside the fuel supply pipe 10, an annular sealing plate 60 that seals the gap between the fuel supply pipe 10 and the inner wall pipe 50 at the tip of the fuel supply pipe 10, a plurality of peeling members 70 protruding from the peripheral surface of the fuel supply pipe 10, a plurality of outlet nozzles 80 extending from the fuel supply pipe 10 downstream of the peeling member 70 in the combustion air ejection direction, and a pilot burner 90 arranged inside the inner wall pipe 50.

[0020] The fuel supply pipe 10 defines a flow path through which the fuel gas is supplied and which guides the fuel gas to the outflow nozzle 80. The fuel gas used in the gas burner 1 may be, for example, hydrogen gas, methane gas, propane gas, or a gas containing hydrogen, but in this embodiment, particularly when using a fuel gas such as electrolytic hydrogen or biogas that has a low gas pressure (close to normal pressure) when generated, the effect of reducing the cost of increasing the pressure of the fuel gas is remarkable.

[0021] The wind box 20 is supplied with combustion air, distributes the supplied combustion air so as not to vary depending on the angular position relative to the fuel supply pipe 10, and introduces the air into the air supply pipe 30.

[0022] The air supply pipe 30 guides the combustion air along the fuel supply pipe 10 to the air outlet 40 in the combustion air ejection direction.

[0023] The air outlet 40 ejects the combustion air in the combustion air ejection direction (downward in Figs. 1 and 2). In the illustrated example, the air outlet 40 is defined by a short pipe 42 disposed on an end plate 41 that seals the tip of the air supply pipe 30. The multiple air outlets 40 are formed to open in an annular region concentric with the fuel supply pipe 10 when viewed in the combustion air ejection direction, in order to form a flow of combustion air along the fuel supply pipe 10 over the entire circumference of the fuel supply pipe 10. The air outlets 40 are preferably provided radially spaced from the fuel supply pipe 10.

[0024] Due to the jet of combustion air ejected from the air ejection port 40, the combustion exhaust gas in the furnace is continuously entrained in the combustion air from the circumferential direction along the flow of the jet toward the fuel gas supply section.

[0025] The diameter of an imaginary circumscribing circle of air nozzle 40 (shown by a two-dot chain line in FIG. 3) is preferably less than twice, and more preferably less than 1.65 times, the outer diameter of fuel supply pipe 10. By not making the diameter of the imaginary circumscribing circle of air nozzle 40 unnecessarily larger than the outer diameter of fuel supply pipe 10, the speed of the combustion air jet can be made constant or higher, and an appropriate separation area of ​​the combustion air can be secured.

[0026] The diameter of an imaginary circle connecting the centers of the air outlets 40 (shown by a dashed line in FIG. 3) is preferably greater than 0.15 and less than 0.7 times the diameter D of the inner space of the can body 110 (the pitch circle diameter of the inner water tube 111, see FIG. 1). This ensures an area in which the jet of combustion air can entrain the combustion exhaust gas, as well as the space necessary for combustion, allowing the combustion exhaust gas to be efficiently entrained in the jet of combustion air while preventing incomplete combustion.

[0027] The inner wall pipe 50 is disposed inside the fuel supply pipe 10 and restricts the cross section of the fuel gas flow path to an annular shape. The inner wall pipe 50 has an expanded diameter portion 51 that expands in diameter to reduce the cross section of the fuel gas flow path upstream of the outflow nozzle 80. Since the inner wall pipe 50 has the expanded diameter portion 51, the flow rate of the fuel gas inside the tip of the fuel supply pipe 10, which is likely to become hot due to combustion, can be cooled by the fuel gas, and the durability of the gas burner 1 can be improved. In particular, since the thermal conductivity of the fuel gas is higher than that of air, the increase in the cooling effect of the fuel supply pipe 10 due to the increase in the flow rate of the fuel gas is not small. In particular, when hydrogen gas is used as the fuel gas, the thermal conductivity of the hydrogen gas is 0.257 W / mk at 200°C, which is nearly seven times the thermal conductivity of air at 200°C, 0.038 W / mk, so the increase in the cooling effect of the fuel supply pipe 10 due to the expanded diameter portion 51 is remarkable.

[0028] The sealing plate 60 terminates the gap between the fuel supply pipe 10 and the inner wall pipe 50, which serves as a flow path for the fuel gas. In other words, the sealing plate 60 forms the end face of the fuel supply pipe 10 on the downstream side in the combustion air ejection direction. This allows the fuel gas to flow out only from the outflow nozzle 80.

[0029] The peeling member 70 constitutes a peeling structure that partially peels off the flow of combustion air from the fuel supply pipe 10 immediately before the outflow nozzle 80. That is, in the gas burner 1, the peeling structure has a plurality of peeling members 70. By separating the flow of combustion air with the peeling members 70, a low-pressure region with low pressure is formed downstream of the peeling member 70. The peeling member 70 that protrudes from the fuel supply pipe 10 has a simple structure and can easily form a desired low-pressure region.

[0030] The peeling members 70 of this embodiment are provided in one-to-one correspondence with the outflow nozzles 80. In order to form a low-pressure region that is sufficiently effective in reducing the fuel supply pressure, it is preferable that the peeling members 70 are larger than the outflow nozzles 80 when viewed from the combustion air ejection direction, and that the peeling members 70 encompass the entire outflow nozzle 80 in their projected shape.

[0031] The outflow nozzles 80 each have a fuel outlet 81 for discharging the fuel gas. The outflow nozzle 80 of this embodiment extends radially from the fuel supply pipe 10 and has a fuel outlet 81 that opens in the extending direction at its tip. The outflow nozzle 80 constitutes an outflow structure for discharging the fuel gas into the low pressure region formed by the peeling member 70. By discharging the fuel gas from the outflow nozzle 80 into the low pressure region formed by the peeling member 70, the supply pressure for discharging the amount of fuel gas required to obtain a desired combustion amount can be reduced. For this reason, the gas burner 1 can be used without pressurizing fuel gas with a low supply pressure, such as by-product hydrogen or low pressure supply city gas, or with reduced pressurization costs.

[0032] By providing the outflow nozzles 80 protruding from the fuel supply pipe 10, it is possible to suppress the combustion exhaust gas or purge air in the furnace from diffusing into the inside of the fuel supply pipe 10 when combustion is stopped. In addition, it is possible to adjust the supply position of the fuel from the fuel supply pipe 10 in the low pressure region. In addition, by discharging the fuel gas from the multiple outflow nozzles 80, it is possible to reduce the bias of the fuel distribution in the circumferential direction of the gas burner 1.

[0033] The outflow nozzle 80 is disposed downstream of the air outlet 40 at a fixed distance from the air outlet 40. By providing the air outlet 40 at a fixed distance from the fuel supply pipe 10, the combustion exhaust gas in the furnace is mixed into the jet of combustion air before the fuel gas is mixed therein.

[0034] The distance L of the outflow nozzle 80 (center of the fuel outlet 81) from the air outlet 40 in the combustion air ejection direction is preferably at least twice the equivalent diameter of the air outlet 40 at which the flow of combustion air ejected from the air outlet 40 is attracted to the outer wall of the fuel supply pipe 10, and is preferably 15 times or less at which a certain degree of air jet speed is maintained, and more preferably 3 to 12 times. By setting the distance L of the outflow nozzle 80 from the air outlet 40 to the lower limit or more, an effective combustion air jet can be formed, and an appropriate separation area of ​​the combustion air can be secured.

[0035] In this embodiment, when viewed in the direction of combustion air ejection, a plurality of outflow nozzles 80, the same number as the air ejections 40, are arranged alternately with the air ejections 40 in the circumferential direction, but the number and angular positions of the outflow nozzles 80 are not limited to the number and angular positions of the air ejections 40 and can be set arbitrarily. The outflow nozzle 80 may be an opening in the fuel supply pipe that has been provided with a rise by burring or the like, or may be an opening that has been three-dimensionally processed into the outer wall of the fuel supply pipe. The outflow nozzle may also be an opening provided on the circumferential surface of the fuel supply pipe.

[0036] The pilot burner 90 has a pilot air pipe 91 to which pilot combustion air is supplied, and a pilot fuel pipe 92 that is arranged inside the pilot air pipe 91 and to which pilot fuel is supplied. The pilot burner 90 mixes the pilot fuel and the pilot combustion air at the tip of the pilot air pipe 91 to form a pilot flame.

[0037] Cooling air may be supplied to the gap between the pilot burner 90 and the inner wall tube 50. This allows the fuel gas and thus the fuel supply pipe 10 to be cooled by the cooling air via the inner wall tube 50, improving the durability of the gas burner 1. The cooling air can utilize a portion of the combustion air, the flow rate of which is set according to the flow rate of the fuel gas supplied to the fuel supply pipe 10.

[0038] As described above, the gas burner 1 allows the fuel gas to flow from the outflow structure having the outflow nozzle 80 into the low pressure region formed by the peeling structure having the peeling member 70, so that even if the supply pressure of the fuel gas is low, a sufficient amount of fuel gas can be caused to flow. In other words, the gas burner 1 can use fuel gas with a low supply pressure, so that the cost of increasing the pressure of the fuel gas can be reduced.

[0039] In the boiler 100, the gas burner 1 is disposed in a space surrounded by a plurality of water tubes 111, so that the flow of the combustion air is not biased in the circumferential direction. Therefore, a uniform low-pressure area is formed in the circumferential direction outside the jet of the combustion air, and the fuel gas is supplied without bias, so that the combustion can be performed uniformly. Therefore, the boiler 100 can efficiently generate steam. In addition, the boiler 100 employs a boiler body 110 that defines a flow path for flowing the combustion exhaust gas of the gas burner 1 in the axial direction of the plurality of water tubes 111, so that the flow rate in the axial direction is not biased and the formation of local high-temperature parts due to combustion can be suppressed, and the pressure loss in the boiler body 110 can be reduced, which has the effect of suppressing the energy of the blower and also has the effect of reducing the supply pressure of the fuel gas.

[0040] Next, a gas burner 1A according to a second embodiment of the present invention will be described. Fig. 4 is a cross-sectional view showing the configuration of the gas burner 1A. In the following description, the same components as those in the previously described embodiment are given the same reference numerals, and duplicated descriptions may be omitted. This gas burner 1A can be used in place of the gas burner 1 in the boiler 100 of Fig. 1.

[0041] The gas burner 1A of this embodiment comprises a fuel supply pipe 10 extending in the direction of combustion air ejection, a wind box 20 arranged to surround the upstream portion of the fuel supply pipe 10, an air supply pipe 30 extending from the wind box 20 so as to be positioned outside the fuel supply pipe 10, a plurality of air ejection ports 40 provided at the tip of the air supply pipe 30 so as to be positioned around the fuel supply pipe 10, an inner wall pipe 50 arranged inside the fuel supply pipe 10, an annular sealing plate 60 at the tip of the fuel supply pipe 10 that seals the gap between the fuel supply pipe 10 and the inner wall pipe 50, a plurality of outlet nozzles 80A extending from the fuel supply pipe 10, and a pilot burner 90 arranged inside the inner wall pipe 50.

[0042] In the gas burner 1A of this embodiment, the outflow nozzle 80A is formed integrally with the peeling member. In the gas burner 1A of this embodiment, the outflow nozzle 80A has a sealed tip, and a fuel outlet 81A opens on the peripheral surface downstream in the combustion air ejection direction. In this embodiment, the outflow nozzle 80A has a peeling structure in which the upstream portion of the pipe wall in the combustion air ejection direction peels off the flow of combustion air from the fuel supply pipe 10. In addition, the outflow nozzle 80A forms an outflow structure that causes the fuel gas to flow into the low-pressure region where the fuel outlet 81A opens.

[0043] In this way, a structure extending from the fuel supply pipe 10 into the flow path of the combustion air and obstructing the combustion air jet can be a separation structure that separates the combustion air flow from the fuel supply pipe 10 and forms a low-pressure region downstream. It is desirable that the outflow structure does not open to a high-pressure region so that the fuel gas can flow out to the low-pressure region. For this reason, it is preferable that the fuel outflow port 81A of the outflow nozzle 80A is formed so as not to directly receive the combustion air jet.

[0044] The gas burner 1A of this embodiment having the above configuration can also use a fuel gas with a low supply pressure.

[0045] 5 shows the configuration of a gas burner 1B according to a third embodiment of the present invention. The gas burner 1B of this embodiment is similar to the gas burner 1A of the second embodiment, except that it has an outlet nozzle 80B whose fuel gas outflow direction is different from that of the outlet nozzle 80A of the second embodiment.

[0046] In the gas burner 1B of this embodiment, the outflow nozzle 80B extends from the fuel supply pipe 10 at an incline downstream in the combustion air ejection direction from the radial direction, and a fuel outlet 81B opens at the tip of the outflow nozzle 80B. By disposing the outflow nozzle 80B at an incline in this manner, the fuel outlet 81B opens downstream in the combustion air ejection direction from the radial direction of the fuel supply pipe 10, and the pipe wall of the outflow nozzle 80B is present upstream of the fuel outlet 81B. For this reason, the pipe wall of the outflow nozzle 80B forms a peeled structure that forms a low-pressure region that includes the fuel outlet 81B, and the fuel outlet 81B forms an outflow structure that allows the fuel gas to flow into the low-pressure region formed by the peeled structure.

[0047] The gas burner 1B of this embodiment can also use a fuel gas with a low supply pressure.

[0048] 6 shows the configuration of a gas burner 1C according to a fourth embodiment of the present invention. The gas burner 1C of this embodiment includes a fuel supply pipe 10C extending in the direction of combustion air ejection, a wind box 20 arranged to surround the upstream part of the fuel supply pipe 10C, an air supply pipe 30 extending from the wind box 20 so as to be arranged outside the fuel supply pipe 10C, a plurality of air ejection ports 40 provided at the tip of the air supply pipe 30 so as to be arranged around the fuel supply pipe 10C, an inner wall pipe 50C arranged inside the fuel supply pipe 10C, an annular sealing plate 60C that seals the gap between the fuel supply pipe 10C and the inner wall pipe 50C at the tip of the fuel supply pipe 10C, and a pilot burner 90 arranged inside the inner wall pipe 50C.

[0049] In the gas burner 1C of this embodiment, the fuel supply pipe 10C has a diameter-reduced portion 11 formed in the middle. This diameter-reduced portion 11 forms a separation structure that causes the combustion air to separate from the fuel supply pipe 10C by suddenly retracting the fuel supply pipe 10C inward. The illustrated diameter-reduced portion 11 has a shape that reduces the diameter of the fuel supply pipe 10C in a stepped manner so as to form a surface perpendicular to the combustion air ejection direction, but may have any curved shape including a free-form surface such as a conical surface or a spherical surface. In the gas burner 1C of this embodiment, since the diameter-reduced portion 11 is provided in the fuel supply pipe 10C, the inner wall pipe 50C does not have an expanded diameter portion.

[0050] The fuel supply pipe 10C has a fuel outlet 12 that opens near the reduced diameter portion 11 and downstream in the combustion air ejection direction. In other words, the fuel outlet 12 formed in the fuel supply pipe 10C is formed to be located within the low-pressure region formed by the reduced diameter portion 11, and forms an outlet structure that allows the fuel gas to flow directly from the fuel supply pipe 10C to the low-pressure region.

[0051] The gas burner 1C of this embodiment can also use a fuel gas with a low supply pressure.

[0052] 7 shows the configuration of a gas burner 1D according to a fifth embodiment of the present invention. The gas burner 1D of this embodiment includes a fuel supply pipe 10D extending in the direction of combustion air ejection, a wind box 20 arranged to surround the upstream part of the fuel supply pipe 10D, an air supply pipe 30 extending from the wind box 20 so as to be arranged outside the fuel supply pipe 10D, a plurality of air ejection ports 40 provided at the tip of the air supply pipe 30 so as to be arranged around the fuel supply pipe 10D, an inner wall pipe 50D arranged inside the fuel supply pipe 10D, an annular sealing plate 60D that seals the gap between the fuel supply pipe 10D and the inner wall pipe 50D at the tip of the fuel supply pipe 10D, and a pilot burner 90 arranged inside the inner wall pipe 50D.

[0053] In the gas burner 1D of this embodiment, the fuel supply pipe 10D has a reduced diameter portion 11D formed by a sealing plate 60D that seals the end of the fuel supply pipe 10D, and this reduced diameter portion 11D, i.e., the sealing plate 60D, is formed with a fuel outlet 61. The reduced diameter portion 11D of this embodiment is the end of the fuel supply pipe 10D, and such an aspect is also understood to be included in the "reduced diameter".

[0054] In the gas burner 1D of this embodiment as well, the reduced diameter portion 11D forms a separation structure that separates the combustion air from the fuel supply pipe 10D, and the fuel outlet 61 forms an outflow structure that causes the fuel gas to flow into the low pressure region formed by the reduced diameter portion 11D. Therefore, in the gas burner 1D of this embodiment as well, a fuel gas with a low supply pressure can be used.

[0055] Although the preferred embodiment of the gas burner according to the present invention has been described above, the present invention is not limited to the above-mentioned embodiment and can be modified as appropriate.

[0056] For example, in the gas burner according to the present invention, the separating member may be a single annular member for separating the flow of combustion air from the fuel supply pipe over the entire circumference, or one separating member may be provided corresponding to a plurality of fuel outlets. Also, the gas burner according to the present invention may be configured to allow fuel gas to flow out from a fuel outlet formed to open on the circumferential surface of the fuel supply pipe 10 into the low pressure region formed by the separating member.

[0057] In addition, in the gas burner according to the present invention, the peeling structure and outflow structure may be formed by cutting the tip of the outflow nozzle extending radially at an angle to form a fuel outflow outlet that opens toward the downstream side in the direction of combustion air ejection.

[0058] Furthermore, in the gas burner according to the present invention, the configuration of the pilot burner is not particularly limited, and it may not be formed with a flow path for supplying cooling air. [Explanation of symbols]

[0059] 1,1A,1B,1C,1D Gas burner 10,10C,10D Fuel supply pipe 11,11D Reduced diameter part 12 Fuel outlet 20 Wind Box 30 Air supply pipe 40,40A Air outlet 41 Termination plate 42 Short tube 50,50C,50D inner wall tube 51 Expanded diameter part 60,60C,60D Sealing plate 61 Fuel outlet 70 Peeling member 80, 80A, 80B Outlet nozzle 81,81A,81B Fuel outlet 90 Pilot Burner 91 Pilot air pipe 92 Pilot fuel line 100 Boiler 110 Can body 111 Water pipe

Claims

1. a fuel supply pipe extending in a predetermined combustion air ejection direction and through which a fuel gas is supplied; an air outlet that opens in an annular region concentric with the fuel supply pipe as viewed in the combustion air outlet direction and that ejects combustion air along the fuel supply pipe in the combustion air outlet direction; a separation structure for at least partially separating the flow of the combustion air from the fuel supply pipe; an outflow structure having a fuel outflow port for outflowing the fuel gas from the fuel supply pipe into a low pressure region formed by separating the flow of the combustion air by the separation structure; Equipped with A gas burner, wherein a distance in a combustion air ejection direction from the air ejection port to a center of the fuel outlet is 3 to 15 times the equivalent diameter of the air ejection port.

2. a fuel supply pipe extending in a predetermined combustion air ejection direction and through which a fuel gas is supplied; an air outlet that opens in an annular region concentric with the fuel supply pipe as viewed in the combustion air outlet direction and that ejects combustion air along the fuel supply pipe in the combustion air outlet direction; a separation structure for at least partially separating the flow of the combustion air from the fuel supply pipe; an outflow structure having a fuel outflow port for outflowing the fuel gas from the fuel supply pipe into a low pressure region formed by separating the flow of the combustion air by the separation structure; Equipped with The gas burner, wherein the peeling structure is a reduced diameter portion formed in the middle or at the terminal end of the fuel supply pipe.

3. 3. The gas burner according to claim 1, wherein the peeling structure comprises a peeling member protruding from a peripheral surface of the fuel supply pipe.

4. 4. The gas burner according to claim 2 or 3, wherein the fuel outlet is an opening formed in the fuel supply pipe.

5. 3. The gas burner according to claim 1, wherein the outlet structure has an outlet nozzle extending from the fuel supply pipe and having the fuel outlet formed so as to open toward a downstream side in the combustion air ejection direction rather than toward a radial direction of the fuel supply pipe.

6. A gas burner according to any one of claims 1 to 5; a can body that is disposed so as to surround the gas burner, has a plurality of water tubes that extend in the direction of ejection of the combustion air, and defines a flow path through which the combustion exhaust gas from the gas burner flows in the axial direction of the plurality of water tubes; A boiler equipped with

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