JP2017142021A - Burner tip, two-fluid burner and boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner tip capable of properly atomizing liquid fuel, a two-fluid burner, and a boiler.SOLUTION: A burner tip includes a fuel chamber into which liquid fuel is introduced, a tip body having at least one ejection hole for spraying the liquid fuel from the fuel chamber, and at least one medium supply pipe configured to guide the spray medium to the ejection hole. In an upstream side region of the ejection hole, the medium supply pipe is inserted into the ejection hole, and in the upstream side region of the ejection hole, in a radial direction of the medium supply pipe, a clearance communicating with the fuel chamber is formed between the medium supply pipe and the ejection hole.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a burner tip, a two-fluid burner, and a boiler.

  In general, a two-fluid burner that atomizes liquid fuel by using the energy of a spray medium is known. In the two-fluid burner, it is important to reduce the particle size of the atomized liquid fuel in order to achieve soot reduction and NOx reduction.

  One of the two-fluid burners is an internal mixing type two-fluid burner in which a mixing chamber is provided inside the burner tip. In this internal mixing type two-fluid burner, liquid fuel and a spray medium are mixed in advance in a mixing chamber inside the burner tip and ejected into a combustion space.

  For example, Patent Documents 1 and 2 describe an internal mixing type two-fluid burner in which a mixing chamber is provided inside a burner tip. Further, in Patent Document 2, the mixing chamber inside the burner chip is connected to a jet hole for injecting atomized liquid fuel into the combustion chamber, a fuel supply passage connected to the fuel supply pipe, and a steam supply pipe. A configuration provided with a steam supply passage is also described.

JP 2003-172505 A JP-A-2015-64131

By the way, in the internal-mixing type two-fluid burner described in Patent Documents 1 and 2, there is a problem that the liquid fuel is not properly atomized due to poor flow of the liquid fuel inside the mixing chamber.
As a result of investigating the cause in more detail, the present inventors have found that the thickness of the liquid film of the liquid fuel formed in the ejection holes becomes non-uniform due to poor flow of the liquid fuel inside the mixing chamber. It was found to be one of the causes that inhibit That is, in the two-fluid burner, the liquid fuel supplied into the mixing chamber is usually mixed with the spray medium and then injected into the combustion space through the ejection holes. At this time, a liquid film is formed on the wall surface of the ejection hole by the liquid fuel. This liquid film is diffused into the combustion space by the fluid energy of the spray medium. However, the flow energy of the liquid fuel is biased by the flow energy of the spray medium supplied into the mixing chamber, and the thickness of the liquid film formed on the inner wall surface of the ejection hole becomes uneven in the circumferential direction. A thick portion may inhibit atomization. For this reason, the situation where liquid fuel is not atomized appropriately will occur.

  In view of the above circumstances, at least some embodiments of the present invention aim to provide a burner tip, a two-fluid burner, and a boiler that can properly atomize liquid fuel.

(1) A burner tip of a combustor according to at least some embodiments of the present invention includes:
A chip body having a fuel chamber into which liquid fuel is introduced, and at least one ejection hole for spraying the liquid fuel from the fuel chamber;
At least one medium supply pipe for guiding the spray medium to the ejection holes;
With
In the upstream region of the ejection hole, the medium supply pipe is inserted into the ejection hole,
In the upstream region of the ejection hole, a gap communicating with the fuel chamber is formed between the medium supply pipe and the ejection hole in the radial direction of the medium supply pipe.

In the burner tip (1), a medium supply pipe is inserted in the upstream region of the ejection hole, and communicates with the fuel chamber between the medium supply pipe and the ejection hole in the radial direction of the medium supply pipe. A gap is formed.
As described above, since the liquid fuel is supplied from the fuel chamber to the ejection hole through the radial gap between the medium supply pipe and the ejection hole, the influence of the flow of the spray medium is suppressed while suppressing the influence of the flow of the ejection medium. A liquid film of liquid fuel having a relatively uniform film thickness can be formed on the inner wall surface. Therefore, unlike the case where the spray medium is directly introduced into the fuel chamber, it is possible to avoid a situation where the liquid film of the liquid fuel on the inner wall surface of the ejection hole is locally thickened, and to form the liquid film uniformly thin. be able to. Thereby, a liquid film can be appropriately diffused by the fluid energy of the spray medium supplied to the upstream side of the ejection hole, and atomization of the liquid fuel can be promoted.

(2) In some embodiments, in the configuration of (1) above,
The medium supply pipe is inserted into the ejection hole only in the upstream region of the ejection hole so that the tip of the medium supply pipe is located between the upstream end and the downstream end of the ejection hole. ,
In the downstream region of the ejection hole, the liquid fuel supplied from the fuel chamber via the gap is mixed with the spray medium supplied from the medium supply pipe.

  According to the configuration of (2) above, the liquid fuel in a relatively thin liquid film and the spray medium are mixed in the downstream region of the ejection hole where the medium supply pipe is not provided, so that the liquid fuel is effectively removed. Can be atomized.

(3) In some embodiments, in the above configuration (1) or (2),
The gap is an annular gap formed by the inner wall surface of the ejection hole and the outer peripheral surface of the medium supply pipe.

  According to the configuration of (3) above, since the annular gap is formed between the inner wall surface of the ejection hole and the outer peripheral surface of the medium supply pipe, the annular gap is uniform in the circumferential direction on the inner wall surface of the ejection hole. An annular liquid film can be formed. Therefore, the liquid fuel can be effectively atomized.

(4) In some embodiments, in any one of the above configurations (1) to (3),
When the insertion length of the medium supply pipe into the ejection hole is L and the size of the gap between the medium supply pipe and the ejection hole is d, the relationship of 5 ≦ L / d ≦ 20 is satisfied. Fulfill.

  According to the configuration of (4) above, in the relationship between the insertion length L of the medium supply pipe into the ejection hole and the size d of the gap between the medium supply pipe and the ejection hole, L / d is set to 5 or more. By setting, the length of the gap between the outer peripheral surface of the medium supply pipe and the inner wall surface of the ejection hole is sufficiently secured, the boundary layer of the flow of liquid fuel passing through the gap is developed, and the gap On the downstream side, a thin liquid film of liquid fuel can flow along the inner wall surface of the ejection hole. Further, since the gap size d is sufficiently reduced with respect to the insertion length L, the liquid film thickness of the liquid fuel can be reduced also for this reason. On the other hand, by setting L / d to 20 or less, it is possible to suppress an increase in pressure loss due to the gap between the medium supply pipe and the ejection hole.

(5) In some embodiments, in any one of the above configurations (1) to (4),
The chip body is
A fuel inlet for introducing the liquid fuel into the fuel chamber from the outer peripheral side of the chip body;
A medium inlet for introducing the spray medium from the rear end side of the chip body into the medium supply pipe;
Including
The medium supply pipe extends in the fuel chamber from the rear end side of the tip body toward the ejection hole.

In the upstream region of the ejection hole, the liquid fuel from the fuel chamber flows through a radial gap between the outer peripheral surface of the medium supply pipe and the inner wall surface of the ejection hole. In this regard, in the configuration of (4) above, the medium supply pipe extends from the rear end side of the chip body toward the ejection hole in the fuel chamber, and the liquid supply around the medium supply pipe in the fuel chamber. Since the fuel flows, the flow of the liquid fuel toward the radial gap in the upstream region of the ejection hole is not hindered by the medium supply pipe.
Therefore, according to the configuration of (5) above, each flow path of the liquid fuel and the spray medium in the fuel chamber is compared with the case where the medium supply pipe is connected to the medium inlet provided on the outer peripheral side of the chip body. The structure can be simplified.

(6) In some embodiments, in any one of the above configurations (1) to (5),
The chip body has a plurality of the ejection holes respectively provided at different positions in the circumferential direction of the chip body,
The plurality of medium supply pipes are respectively inserted into the plurality of ejection holes in the upstream region of the ejection holes.

  According to the configuration of (6) above, the atomized liquid fuel can be injected over a wide range in the circumferential direction of the burner tip, and the mixing state of the atomized liquid fuel and the combustion air is improved. Combustibility can be improved. Further, since the medium supply pipe is inserted in the upstream region of each ejection hole, atomization of the liquid fuel is promoted for the reason described in the above (1), and the combustibility can be effectively improved.

(7) In some embodiments, in any one of the configurations (1) to (6) above,
The chip body has a plurality of the ejection holes provided at different positions in the axial direction of the chip body,
A plurality of the medium supply pipes are respectively inserted into the plurality of ejection holes in the upstream region of the ejection holes;
The plurality of medium supply pipes extend along the axial direction of the chip body and communicate with a medium collecting channel for guiding the spray medium to the plurality of medium supply pipes.

  According to the configuration of (7) above, the atomized liquid fuel can be injected over a wide range in the axial direction of the burner tip, and the mixed state of the atomized liquid fuel and the combustion air is improved. Combustibility can be improved. Further, since the medium supply pipe is inserted in the upstream region of each ejection hole, atomization of the liquid fuel is promoted for the reason described in the above (1), and the combustibility can be effectively improved.

(8) A two-fluid burner according to at least some embodiments of the present invention comprises:
The burner tip according to any one of (1) to (7) above;
A burner body configured to hold the burner tip on the tip side and supply the liquid fuel and the spray medium toward the burner tip;
Is provided.

  According to the two-fluid burner of (8), the burner tip that can appropriately diffuse the liquid film of the liquid fuel by the fluid energy of the spray medium supplied to the upstream side of the ejection hole and promote atomization of the liquid fuel is provided. Therefore, a two-fluid burner capable of reducing dust and NOx can be provided.

(9) A boiler according to at least some embodiments of the present invention includes:
The two-fluid burner described in (8) above;
A furnace that forms a combustion space in which the liquid fuel injected from the two-fluid burner burns;
Is provided.

  According to the boiler of said (9), since the two-fluid burner which can reduce soot and NOx is provided, a highly reliable boiler can be provided.

  According to at least some embodiments of the present invention, the liquid film of the liquid fuel formed on the inner wall surface of the ejection hole can be uniformly thinned so that the fluid of the spray medium supplied to the upstream side of the ejection hole The liquid film can be appropriately diffused by energy, and atomization of the liquid fuel can be promoted.

It is sectional drawing along the axial direction of the two-fluid burner which concerns on one Embodiment. It is a front view (AA view of FIG. 1) of the burner chip | tip in one Embodiment. It is sectional drawing (BB sectional drawing of FIG. 1) of the burner chip | tip in one Embodiment. It is a fragmentary sectional view along the axial direction of the two fluid burner concerning one embodiment. It is sectional drawing along the axial direction of the two-fluid burner which concerns on other embodiment. It is sectional drawing along the axial direction of the two-fluid burner which concerns on other embodiment. It is a figure which shows typically the flow velocity distribution of the liquid fuel in the clearance gap between the medium supply pipe | tube of a burner tip, and an ejection hole. It is a lineblock diagram of the boiler concerning one embodiment.

  Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.

  The overall configuration of a two-fluid burner 1 according to some embodiments will be schematically described with reference to FIG. In addition, FIG. 1 is sectional drawing along the axial direction of the two-fluid burner 1 which concerns on one Embodiment. In the present embodiment, the axial direction is a direction along the central axis O of the two-fluid burner 1 or the burner tip 10.

  The two-fluid burner 1 according to some embodiments includes a burner body 2 and a burner tip 10 held at the tip of the burner body 2.

The burner body 2 is configured to hold the burner tip 10 on the tip side and supply the liquid fuel F and the spray medium S toward the burner tip 10.
For example, the burner body 2 includes a liquid fuel pipe 3 for supplying the liquid fuel F toward the burner chip 10 and a spray medium pipe 4 for supplying the spray medium S toward the burner chip 10. Prepare.
A burner tip 10 is detachably attached to a burner body 2 including a liquid fuel pipe 3 and an atomizing medium pipe 4 by a tightening ring 9.
The liquid fuel pipe 3 communicates with the fuel chamber 12 of the burner tip 10 via the fuel inlet portion 13. The spray medium pipe 4 communicates with the medium supply pipe 16 of the burner chip 10 through the medium inlet portion 17. The liquid fuel pipe 3 or the spray medium pipe 4 may be provided along the axial direction.

Next, a specific configuration of the burner chip 10 will be described with reference to FIGS.
FIG. 2A is a front view of the burner tip 10 in one embodiment (a view taken along the line AA in FIG. 1). FIG. 2B is a cross-sectional view (cross-sectional view taken along the line BB in FIG. 1) of the burner tip 10 according to an embodiment. FIG. 3 is a partial cross-sectional view along the axial direction of the two-fluid burner 1 according to an embodiment. FIG. 4 is a cross-sectional view along the axial direction of the two-fluid burner 1 according to another embodiment. FIG. 5 is a cross-sectional view along the axial direction of a two-fluid burner 1 according to still another embodiment.
3 to 5 described below, the burner body 2 has the same configuration as that of FIG. 1 described above, but the configuration of the burner body 2 is not limited to this.

As illustrated in FIGS. 1 to 5, a burner tip 10 according to some embodiments includes a fuel chamber 12 into which liquid fuel F is introduced, and at least for spraying liquid fuel F from the fuel chamber 12. A chip body 11 having one ejection hole 14 and at least one medium supply pipe 16 for guiding the spray medium S to the ejection hole 14 are provided.
In the medium supply pipe 16, the medium supply pipe 16 is inserted into the ejection hole 14 in the upstream region 14 a of the ejection hole 14.
In the upstream region 14 a of the ejection hole 14, a gap 20 that communicates with the fuel chamber 12 is formed between the medium supply pipe 16 and the ejection hole 14 in the radial direction of the medium supply pipe 16.
For example, the gap 20 is an annular gap formed by the inner wall surface 14 e of the ejection hole 14 and the outer peripheral surface 16 a of the medium supply pipe 16.

In the configuration example shown in FIG. 1, the fuel chamber 12 is formed in an annular shape around the central axis O of the burner tip 10. On the other hand, in the configuration example shown in FIG. 3, the fuel chamber 12 is formed in a tubular shape around the central axis O of the burner tip 10.
The medium supply pipe 16 has a region provided in the fuel chamber 12 along the extending direction of the fuel chamber 12, and a region provided in the ejection hole 14 provided along the extending direction of the ejection hole 14. May be.

As described above, since the liquid fuel F is supplied from the fuel chamber 12 to the ejection hole 14 via the radial gap 20 between the medium supply pipe 16 and the ejection hole 14, the influence of the flow of the spray medium S is affected. While being suppressed, a liquid film of the liquid fuel F having a relatively uniform film thickness can be formed on the inner wall surface 14e of the ejection hole 14. Therefore, unlike the case where the spray medium S is directly introduced into the fuel chamber 12, a situation in which the liquid film of the liquid fuel F on the inner wall surface 14e of the ejection hole 14 becomes locally thick can be avoided, and the liquid film can be made uniform. Can be formed thin. Thereby, the liquid film can be appropriately diffused by the fluid energy of the spray medium S supplied to the upstream side of the ejection hole 14, and atomization of the liquid fuel F can be promoted.
Further, an annular gap 20 is formed by the inner wall surface 14e of the ejection hole 14 and the outer circumferential surface 16a of the medium supply pipe 16, so that in the annular gap 20, the inner wall surface 14e of the ejection hole 14 is uniform in the circumferential direction. An annular liquid film can be formed. Therefore, the liquid fuel F can be effectively atomized.

Further, the medium supply pipe 16 has an ejection hole only in the upstream region 14a of the ejection hole 14 so that the front end portion 16b of the medium supply pipe 16 is located between the upstream end 14a1 and the downstream end 14b1 of the ejection hole 14. 14 may be inserted.
In this case, in the downstream region 14 b of the ejection hole 14, the liquid fuel F supplied from the fuel chamber 12 through the gap 20 and the spray medium S supplied from the medium supply pipe 16 are mixed. The

  According to the above configuration, the liquid fuel F having a relatively thin liquid film and the spray medium S are mixed in the downstream region 14b of the ejection hole 14 where the medium supply pipe 16 is not provided, so that the liquid fuel F is effective. Can be atomized.

In the embodiment illustrated in FIGS. 1, 2 </ b> A, and 2 </ b> B, the chip body 11 has a plurality of ejection holes 14 provided at different positions in the circumferential direction of the chip body 11. For example, in the configuration illustrated in FIG. 2, the chip body 11 is provided with eight ejection holes 14 at equal intervals in the circumferential direction.
In this case, a plurality of medium supply pipes 16 are respectively inserted into the plurality of ejection holes 14 in the upstream region 14 a of the ejection holes 14.

  According to the above configuration, the atomized liquid fuel F can be injected over a wide range in the circumferential direction of the burner tip 10, and the mixing state of the atomized liquid fuel F and combustion air is improved and combustion is performed. Can be improved. Further, since the medium supply pipe 16 is inserted in the upstream region 14a of each ejection hole 14, the atomization of the liquid fuel F is promoted for the reason described above, and the combustibility can be effectively improved.

  As illustrated in FIG. 3, in the burner tip 10 described above, the insertion length of the medium supply pipe 16 into the ejection hole 14 is L, and the size of the gap between the medium supply pipe 16 and the ejection hole 14 is d. In this case, the relationship of 5 ≦ L / d ≦ 20 may be satisfied.

Here, the flow phenomenon of the liquid fuel in the gap 20 between the medium supply pipe 16 and the ejection hole 14 of the burner tip 10 will be described with reference to FIG. FIG. 6 is a diagram schematically showing the flow velocity distribution of the liquid fuel F in the gap 20 between the medium supply pipe 16 and the ejection hole 14 of the burner tip 10. In the same figure, as an example, a case where at least a part of the inlet portion 20a of the gap 20 spreads in a bell mouth shape toward the downstream side will be described so as to facilitate understanding.
As shown in FIG. 6, the liquid fuel F (fluid) flowing through the gap 20 between the inner wall surface 14 e of the ejection hole 14 and the outer peripheral surface 16 a of the medium supply pipe 16 has no boundary layer at the inlet 20 a of the gap 20. Due to its development, it has a uniform flow velocity distribution in the width direction. Here, the width direction coincides with the radial direction R of the front end portion 16 b of the medium supply pipe 16.
The boundary layer develops toward the downstream side from the inlet portion 20a of the gap 20, and the boundary layer is stabilized at a certain distance from the inlet portion 20a toward the downstream side with respect to the size d of the gap.

According to the above configuration, L / d is 5 or more in the relationship between the insertion length L of the medium supply pipe 16 into the ejection hole 14 and the size d of the gap 20 between the medium supply pipe 16 and the ejection hole 14. By setting to, the length of the gap 20 between the outer peripheral surface 16a of the medium supply pipe 16 and the inner wall surface 14e of the ejection hole 14 is sufficiently secured, and the flow of the liquid fuel F passing through the gap 20 is ensured. The boundary layer is developed, and the liquid fuel F having a thin liquid film can flow along the inner wall surface 14e of the ejection hole 14 on the downstream side of the gap 20.
Further, since the size d of the gap 20 is sufficiently reduced with respect to the insertion length L, the liquid film thickness of the liquid fuel F can be reduced for this reason.
On the other hand, by setting L / d to 20 or less, an increase in pressure loss due to the gap 20 between the medium supply pipe 16 and the ejection hole 14 can be suppressed.

In the embodiment illustrated in FIGS. 1, 4, and 5, the chip body 11 includes a fuel inlet 13 for introducing the liquid fuel F into the fuel chamber 12 from the outer peripheral side of the chip body 11, and the chip body 11. And a medium inlet portion 17 for introducing the spray medium S into the medium supply pipe 16 from the rear end side.
In this configuration, the medium supply pipe 16 extends in the fuel chamber 12 from the rear end side of the chip body 11 toward the ejection hole 14.

In the upstream region 14 a of the ejection hole 14, the liquid fuel F from the fuel chamber 12 flows through the radial gap 20 between the outer peripheral surface 16 a of the medium supply pipe 16 and the inner wall surface 14 e of the ejection hole 14. In this regard, in the configuration described above, the medium supply pipe 16 extends from the rear end side of the chip body 11 toward the ejection hole 14 in the fuel chamber 12. Since the liquid fuel F flows around, the medium supply pipe 16 does not hinder the flow of the liquid fuel F toward the radial gap 20 in the upstream region 14 a of the ejection hole 14.
Therefore, according to the above configuration, the liquid fuel F and the spray medium S are contained in the fuel chamber 12 as compared with the case where the medium supply pipe 16 is connected to a medium inlet portion (not shown) provided on the outer peripheral side of the chip body 11. Each flow path structure can be simplified.

In the embodiment illustrated in FIG. 5, the chip body 11 has a plurality of ejection holes 14 provided at different positions in the axial direction of the chip body 11.
The plurality of medium supply pipes 16 are respectively inserted into the plurality of ejection holes 14 in the upstream region 14 a of the ejection hole 14. Further, the plurality of medium supply pipes 16 extend along the axial direction of the chip body 11 and communicate with a medium collecting channel 19 for guiding the spray medium S to the plurality of medium supply pipes 16.

  According to the above configuration, the atomized liquid fuel F can be injected over a wide range in the axial direction of the burner tip 10, and the mixing state of the atomized liquid fuel F and combustion air is improved and combustion is performed. Can be improved. Further, since the medium supply pipe 16 is inserted in the upstream region 14a of each ejection hole 14, the atomization of the liquid fuel F is promoted for the reason described above, and the combustibility can be effectively improved.

Also in the embodiment illustrated in FIG. 5, the chip body 11 may have a plurality of ejection holes 14 provided at different positions in the circumferential direction of the chip body 11 (see FIG. 2A).
In this case, the plurality of medium supply pipes 16 are respectively inserted into the plurality of ejection holes 14 in the upstream region 14 a of the ejection hole 14.

  According to the above configuration, the atomized liquid fuel F can be injected over a wide range in the circumferential direction of the burner tip 10, and the mixing state of the atomized liquid fuel F and combustion air is improved and combustion is performed. Can be improved. Further, since the medium supply pipe 16 is inserted in the upstream region 14a of each ejection hole 14, the atomization of the liquid fuel F is promoted for the reason described above, and the combustibility can be effectively improved.

  Next, with reference to FIG. 7, a boiler 50 as an example of an application destination of the above-described two-fluid burner 1 will be described. However, the application destination of the above-described two-fluid burner 1 is not limited to the boiler 50, and can be used in other combustion apparatuses.

  A boiler 50 according to some embodiments includes the above-described two-fluid burner 1 and a furnace 52 that forms a combustion space 100 in which liquid fuel F injected from the two-fluid burner 1 burns.

  More specifically, in the embodiment illustrated in FIG. 7, the boiler 50 includes a combustion device 51 including the two-fluid burner 1 and a furnace 52. For example, the boiler 50 uses heavy oil (or light oil, pitch, etc.) as the liquid fuel F as fuel, and the heavy oil is vapor (or high pressure air, high pressure) as the spray medium S by the two-fluid burner 1 (burner chip 10). It is an oil-fired boiler configured to atomize and spray with gas, flammable gas, etc., burn in the furnace 52, and recover the heat generated by this combustion.

The furnace 52 is provided such that the combustion space 100 extends in the vertical direction, and a heat transfer tube is disposed on the furnace wall 53 that defines the combustion space 100. A combustion device 51 is provided below the furnace wall 53.
The combustion device 51 has a plurality of two-fluid burners (combustion burners) 1 disposed on the furnace wall 53. For example, a plurality of two-fluid burners 1 are arranged along the circumferential direction or vertical direction of the furnace 52. The two-fluid burner 1 includes the burner tip 10 (see FIGS. 1 to 6) shown in any of the above-described embodiments.

  Each of the two-fluid burners 1 is supplied with fuel from a fuel supply source 61 through a liquid fuel pipe 3 (see also FIG. 1) and from a vapor supply source 63 through a spray medium pipe 4 (see also FIG. 1). Medium). In addition, combustion air heated by exchanging heat with exhaust gas is supplied from the air duct 65 to the wind box 66 to each two-fluid burner 1. Therefore, the two-fluid burner 1 mixes fuel and the above and atomizes them, and then injects them into the furnace 52 as a mixed fluid, and injects combustion air into the furnace 52 to form a flame in the furnace 52. Can do. The combustion gas generated in the furnace 52 is exhausted through a flue 60 connected to the upper part of the furnace 52. The flue 60 is provided with a superheater, a reheater, a economizer, or the like as a heat recovery unit, and recovers the heat of the combustion gas.

  According to the above boiler, since the two-fluid burner capable of reducing dust and NOx can be provided, a highly reliable boiler can be provided.

  As described above, according to at least some embodiments of the present invention, the liquid film of the liquid fuel formed on the inner wall surface of the ejection hole can be uniformly thinned and supplied to the upstream side of the ejection hole. The liquid film can be appropriately diffused by the fluid energy of the spray medium, and atomization of the liquid fuel can be promoted.

  The present invention is not limited to the above-described embodiments, and includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expression “comprising”, “including”, or “having” one constituent element is not an exclusive expression that excludes the presence of the other constituent elements.

DESCRIPTION OF SYMBOLS 1 Two-fluid burner 2 Burner main body 3 Liquid fuel pipe 4 Spray medium pipe | tube 10 Burner tip 11 Tip main body 12 Fuel chamber 13 Fuel inlet part 14 Ejection hole 14a Upstream area 14a1 Upstream end 14b Downstream area 14b1 Downstream end 14e Inner wall surface 16 Medium Supply pipe 16a Outer peripheral surface 16b Tip portion 17 Medium inlet portion 19 Medium collecting passage 20 Clearance 20a Inlet portion 50 Boiler 51 Combustion device 52 Furnace 100 Combustion space

Claims (9)

A chip body having a fuel chamber into which liquid fuel is introduced, and at least one ejection hole for spraying the liquid fuel from the fuel chamber;
At least one medium supply pipe for guiding the spray medium to the ejection holes;
With
In the upstream region of the ejection hole, the medium supply pipe is inserted into the ejection hole,
In the upstream region of the ejection hole, a gap communicating with the fuel chamber is formed between the medium supply pipe and the ejection hole in the radial direction of the medium supply pipe. . The medium supply pipe is inserted into the ejection hole only in the upstream region of the ejection hole so that the tip of the medium supply pipe is located between the upstream end and the downstream end of the ejection hole. ,
In the downstream area of the ejection hole, the liquid fuel supplied from the fuel chamber through the gap and the spray medium supplied from the medium supply pipe are mixed. The burner chip according to claim 1.   The burner tip according to claim 1 or 2, wherein the gap is an annular gap formed by an inner wall surface of the ejection hole and an outer peripheral surface of the medium supply pipe.   When the insertion length of the medium supply pipe into the ejection hole is L and the size of the gap between the medium supply pipe and the ejection hole is d, the relationship of 5 ≦ L / d ≦ 20 is satisfied. The burner tip according to any one of claims 1 to 3, wherein the burner tip is satisfied. The chip body is
A fuel inlet for introducing the liquid fuel into the fuel chamber from the outer peripheral side of the chip body;
A medium inlet for introducing the spray medium from the rear end side of the chip body into the medium supply pipe;
Including
5. The burner tip according to claim 1, wherein the medium supply pipe extends in the fuel chamber from a rear end side of the tip body toward the ejection hole. 6. . The chip body has a plurality of the ejection holes respectively provided at different positions in the circumferential direction of the chip body,
6. The burner tip according to claim 1, wherein a plurality of the medium supply pipes are respectively inserted into the plurality of ejection holes in the upstream region of the ejection holes. The chip body has a plurality of the ejection holes provided at different positions in the axial direction of the chip body,
A plurality of the medium supply pipes are respectively inserted into the plurality of ejection holes in the upstream region of the ejection holes;
The plurality of medium supply pipes extend along an axial direction of the chip body and communicate with a medium collecting channel for guiding the spray medium to the plurality of medium supply pipes. The burner tip according to any one of claims 1 to 6. The burner tip according to any one of claims 1 to 7,
A burner body configured to hold the burner tip on the tip side and supply the liquid fuel and the spray medium toward the burner tip;
A two-fluid burner comprising: A two-fluid burner according to claim 8;
A furnace that forms a combustion space in which the liquid fuel injected from the two-fluid burner burns;
A boiler characterized by comprising.

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